Green Energy and Technology Om Prakash Anil Kumar Solar Drying Technology Concept, Design, Testing, Modeling, Economics, and Environment Green Energy and Technology More information about this series at http://www.springer.com/series/8059 Om Prakash • Anil Kumar Editors Solar Drying Technology Concept, Design, Testing, Modeling, Economics, and Environment Editors Om Prakash Department of Mechanical Engineering Birla Institute of Technology, Mesra Ranchi, Jharkhand, India Anil Kumar Department of Energy (Energy Centre) Maulana Azad National Institute of Technology Bhopal, Madhya Pradesh, India ISSN 1865-3529 ISSN 1865-3537 (electronic) Green Energy and Technology ISBN 978-981-10-3832-7 ISBN 978-981-10-3833-4 (eBook) DOI 10.1007/978-981-10-3833-4 Library of Congress Control Number: 2017949696 © Springer Nature Singapore Pte Ltd 2017 This work is subject to copyright All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed The use of general descriptive names, registered names, trademarks, service marks, etc in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer Nature Singapore Pte Ltd The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore Foreword by Akhtar Kalam At the present situation, for the major chunk of global population, satisfying their basic needs like energy, food, clean water and housing cannot be achieved because of the demand for energy is far much higher than the supply In this age of energy crisis, there is a strong urge to look for renewable energy sources for the fulfillment of our basic energy need It is not only provide the energy security but save our precious environment from greenhouse gasses Solar energy has emerged as one of the prominent renewable energy Solar radiation is another term used for electromagnetic radiation By the proper utilization of the radiation, various important activities can be done like drying, water purification, electricity generation, space heating, crop cultivation etc For developing nations like India, solar food processing is the newest and efficient advanced technology introduced for addressing different problems faced by our citizens The technology which includes food processing and storage using solar energy can indirectly aid in removing poverty We not produce less; the fact is that much of our produce goes as waste as we not have proper food processing and preservation mechanism in our country By introducing solar drying technology to our farmers, a revolution can be started and absolute poverty and hunger can be wiped from our country In majority of Asian countries, agriculture mostly dominates economy More than half the population is employed in agriculture but still the demand outdoes the supply One of the major reasons for this being lack of efficient preservation and storage techniques One of the most popular techniques for preserving food in most of the Asian countries is drying of crops by employing solar energy Application of solar energy in drying for preserving agricultural and marine produce is in practice since ages This was done using direct solar radiations Solar dryers have huge applications in agriculture and industrial sector; especially from an energy point of view, dryers are the most useful devices These can save energy, save plenty of time, occupy minimal surface area, enhance life and quality of products and most importantly are ecofriendly Drying rice using solar dryers has been well known for many years especially in the countries producing rice, such as v vi Foreword by Akhtar Kalam Thailand and the other Asian countries Solar dryers can be used effectively for low temperature drying and hence can be used effectively to dry agricultural produce, flowers, herbs etc Thus, solar dryers overcome various disadvantages of artificial mechanical dryers, reducing the total amount of fuel energy required This book has sections and covers 23 chapters These sections are: (i) (ii) (iii) (iv) (v) Concept of Solar Drying Design and Testing of Solar Drying Systems Modelling of Solar Drying Systems Environomical Impact of Solar Drying Systems Innovation in Solar Drying This book edited by Dr Anil Kumar, who was a respected researcher at the Energy Technology Research Centre, Department of Mechanical Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Thailand, and at present, Assistant Professor, Dept of Energy (Energy Centre), Maulana Azad National Institute of Technology, Bhopal (India), and Dr Om Prakash, Assistant Professor, Department of Mechanical Engineering, from Birla Institute of Technology Mesra, Ranchi-India, is extremely well written and the authors of various chapters have substantial analytical and theoretical knowledge in the subject A comprehensive review of the various designs, details of construction and operational principles of the wide variety of practicallyrealised designs of solar-energy drying systems has been presented I commend this book to all undergraduates, postgraduates, researchers and academics interested in acquiring knowledge in this important area The appropriateness of each design type for application by rural farmers and others in developing countries has been discussed Some very recent developments in solar drying technology have also been highlighted Smart Energy Research Unit, College of Engineering and Science (D524 or D332) Victoria University Ballarat Road, Footscray, 3011, VIC, Australia Akhtar Kalam Foreword by D P Kothari Solar energy is an ancient subject In India, the Sun is considered to be God Women worship the Sun In fact, all forms of energy emanates from the Sun only In the future, solar energy will form the major chunk of the energy supplied India is lucky to have Sun for 220 days in most parts out of 365 days There are several aspects of solar science and engineering which the students, teachers, researchers and industry personnel have to study, such as solar power generation by PV and solar thermal, solar refrigeration, solar cooker, solar cooling and heating, solar drying, and solar architecture Out of these, solar drying finds a special place The book Solar Drying Technology: Concept Design Testing Modeling Economics and the Environment edited by my friends Dr Om Prakash and Dr Anil Kumar will fulfil the long felt need of a book in this vital area It will prove to be a good text/reference book The main strength of this book is its beauty of combining theory and practice in various chapters written by well-known international experts in the area Both the editors are well known to me and they have done a fabulous job As a co-author/co-editor of more than 50 books and as one who has also worked in solar energy and was in the illustrious company of great solar energy experts like Prof M.S Sodha, Prof S.S Mathur, Prof H.P Garg, Prof G.N Tiwari, Prof T.C Kandpal and other erstwhile colleagues in the Center for Energy studies, IIT Delhi for 30 years, I can safely vouch for the quality of the book I am sure the readers will immensely benefit by this book Indian Institute of Technology, Delhi New Delhi, 110016, Delhi, India D P Kothari vii Foreword by Trilochan Mohapatra Food preservation is very important for food safety and security Food and Agriculture Organization (FAO) estimated that 852 million people worldwide are undernourished The global challenge to ensuring food and nutritional security for the fast-growing human population can be addressed through technological development and innovation in agricultural sector Technology intervention is essential to safeguard against post-harvest losses of agri-produce that continue to happen owing to primitive methods of harvests, handling and storage Drying of agricultural products is one of the important methods to preserve and enhance shelf-life Although open sun drying is a very common and cost- effective method, its advantage is partly upset due to quantitative and qualitative losses caused by rodents, birds, insects, dust, rain, over drying and/or under drying It is extremely important, therefore, to develop energy-efficient drying operations to conserve conventional energy without affecting the quality of the end product In this regard, solar dryers not only meet the drying requirements of crops, fish and animal products, but also save time, energy and money I am happy to record that this book is a joint venture of national and international experts whose ideas have been meticulously compiled by the editors highlighting the concept, design, testing, modelling, economics and environmental perspectives of solar dryers for plausible reading and functional adoption The editors and the authors deserve appreciation for this timely effort Indian Council of Agricultural Research Krishi Bhavan New Delhi, 110001, Delhi, India 21 November 2016 Trilochan Mohapatra ix Preface The tremendous rise in demand for energy has led to scarcity of conventional sources of energy like fossil fuels, thereby pushing us to search for alternative sources of energy With the sun being the ultimate source of energy, we need to harness its energy to sustain the growth of mankind Solar drying has been in practice since ages to preserve different kinds of agricultural produce Due to advancement in science and technology, we have developed inexpensive and efficient solar drying devices for drying different agricultural and marine products using solar power Using solar dryer, the amount of moisture can be reduced tremendously, thus preserving the products for a longer time It reduces product wastage and enhances the productivity of farmers This book is divided in five parts The first part deals about the concept of solar drying In this part, there are five chapters (1, 2, 3, 4, and 5) In Chap 1, the authors discussed the fundamental concepts of drying such as water activity and its significance, the important properties of air and its products, drying mechanism, drying curves and the performance indicators of a dryer The fundamental knowledge in drying will enable a better understanding of any solar drying system In Chap 2, the author discusses the general classification of solar drying systems Numerous types of solar dryers have been designed and developed in various parts of the world A solar dryer can be operated based on either natural or forced convection of heat transfer Based on the mode of heating source, a solar dryer is classified broadly in three types, namely, direct, indirect and mixed mode solar dryer The most typical solar dryers for agricultural produce based on their construction designs were described The selection of solar drying systems should consider the available insolation rate in the target region, kind of product that will be dried, production throughput and operational and investment costs Most studies consider solar drying as a good alternative to traditional open air drying and/or conventional drying systems operated by fossil fuels xi ... cooker, solar cooling and heating, solar drying, and solar architecture Out of these, solar drying finds a special place The book Solar Drying Technology: Concept Design Testing Modeling Economics and. .. Energy and Technology More information about this series at http://www.springer.com/series/8059 Om Prakash • Anil Kumar Editors Solar Drying Technology Concept, Design, Testing, Modeling, Economics,. .. Krishna Nandan Pandey and Smt Indu Devi and the late Sh Tara Chand and Smt Vimlesh and our siblings for their unselfish efforts to help in all fields of life Contents Part I Concept of Solar Drying